Combustion apparatus



June 11, 1940.

D. J. MossHART COMBUSTION-APPARATUS Original Filed April 19, 1935 2 Sheets-Sheet 1 2 G. F Z

INVENTOR I June; 11, 1940. D. J. MOSSHART couauswrou Armmgus Original Filed April 19,1935 2 Sheets-Sheet 2 IINVENTOR Patented June 11, 1940 v UNITED STATES.

2,204,317 -COMBUSTION APPARATUS Donald J. Mosuhart, Springfield-Pas assignor of one-half to Harold F. Bildreth, Long Meadow,

Original application April 19,1935, Serial No.

17,162. Dlvl dad and this application December'7, 1936, Serial No. 114,601

13 Claims. (015110-410) v the broken-up ash as it is discharged through V My invention relates ,to combustion apparatus. and more particularly to stoker-flred furnaces having means for discharging. and crushing the ash; the present application being a division of my copending application Serial'No. 17,162, filed April 19,1935, and patented Jan. 10, 1939, Patent ,No. 2,143,834.

One object of my invention is to provide apparatus of the abovev type which is of improved construction and arrangement of parts.

A further object is to provide an improved form of Stoker-fired furnace which is capable of burning fuel efficiently without requiring the services of an attendaninand wherein provision is made for the mechanical or automatic ejection of ash and also for reducing the size of the larger ash particles so as to facilitate handling of the a'sh.

A, further and more specific object is to pro- ,vide a Stoker-fired furnace including as, a part thereof an ash discharge and crushing which is capable of being adjusted as to its operation'so as to vary the rate of ash discharge and the size of the particles of ash, whereby the apparatus maybe used with a wide variety of fuels and under different conditions without necessitating changes in construction.

Theseand other objects are effected by. my invention, as will be apparent from the following description and claims, taken in connection with the accompanying drawingsforming a part of this application, and in whicha Fig. 1 is a side elevational view showing my improvement as embodied in a household furnace: Fig. 2 is a vertical sectional view taken on the line 11-11 of Fig. l, and showing certain parts of the operating mechanism in elevation for the purposes of clarity; and I u Fig. 3 is a vertical sectional view taken on the 40 line III-III of Fig. 2.

Referring now in detail to the construction illustrated, the referencenumeral II indicates, in its entirety, a stoker-firedfurnace of the type capable of heating a dwelling house or small apartment house, commonly referred to as'a domestic stoker furnace. The furnace ll comprises in general a combustion chamber ii, a fuel supporting surface i2extending' across the lower 5 end of the combustion chamber, a source of fuel supply IS, a means It for'feeding fuel into the combustion chamber, an ash discharge orifice ii extending laterally across the rear of. the fur-- nace, an ash crushing means [6, and a replacea- 55 ble ash receptacle or canl'l disposed to receive the orifice it. v

The combustion chamber ii; is defined byv a front wall 8, a rear wall ,9, and side walls, It

and IS. The fuel supporting-surface I2 is composed ofa stationary guide or supporting plate 20 extending entirely across the bottom of the chamber II, and a grate structure 2| resting on the plate 23 and adapted to be reciprocated forwardlyand rearwardly of the chamber to break up the fuel bed and to eed the burning fuel and o resultant ashrearwardly .of the furnace and to positively eject theash laterally from the combustion chamber il through the orl'fice l5 The ash discharge orifice is defined by the lower horizontal edge of the rear wall 9, the rear end of; the plate 20 and the side walls I8 and I 9;.

The grate structure 2] comprises a grate: frame 22 and a plurality of grate bars 23 detachably mounted in the frame 22'. The plate 20 is suitably. supported by horizontally aligned brackets 24' extending inwardly of the furnace from the lower ends of the walls l8 and 19 defining the combustion chamber, and is provided with an opening 25 through which air for supporting combustion flows from a plenum chamber or wind box 26 arranged below the'plate 20. The air is supplied to the wind box 28 by a blower'2l and such air flows upwardly into the fuel bed through suitable. openings provided in the grate grate bars. 1 1 v The grate frame 22 and grate bars 23 are constructed at their forward end in the form of a U to provide a'fuel feeding, opening 30 communicating with the means It for feeding fuel. a The latter comprises anupwardly inclined duct 3| bars 23 and through the usual spaces between the and a rotatable screw 32 extending longitudinally of the ductll. The lower end of the "duct 3| communicates with the source of fuel supply l3, here shown tobe in the formof a fuel hopper,

which feeds the fuel by gravity to the lower end of the duct 3i and screw 32. It will be appreelated that by rotating the screw 32 the fuel is fed upwardly through the'duct 3| and through the opening 30 into the combustion chamber II.

The fuel-feeding screw 32 may be rotated by any suitable means. Forexample, 'I' have shown.

an electric motor 35 connected by a pulley and belt connection 36 to a suitable form of speedreducing mechanism arranged within a housing 31 beneath the hopper 33. The mechanism in the housing 31 includes a driven shaft 38 extending horizontally out of the housing and;having a bevel gear 39 suitably keyed to the outer end thereof. The gear 39 meshes with a second bevel gear 40 which is suitably keyed to the lower also provided with a pair of spaced downwardly extending projections \44 and aligned journal bearings 45 are provided respectively in the lower ends of these projections. The'bearings receive a grate-operating shaft 46, and one end of the shaft 46 extends outside of the furnace, and an operating arm 41 is' suitably keyed to the outer extension thereof. A pair of spaced operating arms 48 are suitably keyed to the shaft 46 and extend upwardly and are connected respectively at their upper ends to the downwardly extending lugs 43 of the grate by a pair of links 49. Thus, when the shaft 46 is oscillated by power applied 'to the arm 41, the grate frame 22, with the grate bars 23 mounted therein, is moved forwardly and rearwardly through the operating connection formed by the arms 48, links 49 and lugs 43.

The arm 41 is operatively, connected to the driven shaft 38 of the speed-reducing mechanism contained in the housing 31 by means of a crank 50 suitably keyed to the extreme, outer end of the shaft 38 and a connecting link 5|. Thus, when the shaft 38 rotates, the rotary motion thereof is transmitted into oscillatory motion of the shaft 46 through the medium of the crank 50, link 5| and arm 41. The link 5| is pivotally connected to the arm 41 by a removable pin 52 adapted to fit any desired one of a series of holes 53 in the arm 41. Thus, the grate frame with the grate bars therein is reciprocated forwardly and rearwardly on the guide plate 20, and the amplitude of the reciprocations may be readily varied v In my copending application above referred to, of which this application is a division, I have described in detail the improved and efficient operation effected by the structure so far described. I have also described and illustrated the particular type of fuel bed maintained in the combustion chamber II and the detail action carried on in the fuel bed. These features are claimed in my copending application: It is believed sufficient for a clear understanding of the present invention to state that in normal operation the burning fuel bed extends entirely across the lower part of the chamber from front wall 8 to rear wall 9 and from side wall Hi to side wall l9; and that fresh fuel is fed in an upwardly inclined direction into the fuel bed and upwardly and towards the rear wall 3 by the screw 32 rotating in the upwardly inclined duct 3| which terminates at the opening 30. The fuel bed is agitated and is aided in its rearward movement by the reciprocating grate 2|. As the fuel burns, ash is formed and gravitates to the. lower part of the bed where itis fed rearwardly and laterally" out of the'orifice l5 by-the grate 2|.

As explained in my copending application, it is desirable that the rate of ash discharge be so regulated with respect to the rate of fuel feed, the fuel burning rate, and the ash content of the fuel, that a substantial bed of ash is alwaysfuel; two, to prevent the harmful infiltration of excess air into the furnace through the ash discharge orifice l5; and three, to offer a substantial resistance to the flow of air into the furnace at the rear so that air in sufficient quantities passes through the bed at the front of the furnace where the resistance is normally high due to the greater degree of coking action. This third reason is, of course, present when a coking coal is being burned.

According to the present invention, my'improved form of ash crushing means IS, in conjunction with the regulatable action of the reciprocating grate 2|, provides for the desired maintenance of a bed of ash adjacent the orifice,

'andprovides for a variable rate of ash discharge from the combustion chamber to suit any type of I5 and" at the rear of the wall 9 to partially close the orifice IS. The plate 60 is confined to its vertical movement by guide means arranged at each end thereof and comprising vertical guide plates 6| secured respectively to the end walls I! and I9 and spaced from the adjacent ends of the vertical rear wall 9.

The plate 60 is provided with teeth 62 on its lower forward surface which serve to feed the ash and clinker downwardly toward the orifice, and also to crush and break up the clinker. As the plate is moved downward and against the ash, the lower horizontal edge of the plate will shear or crush any clinker or large ash particles as the latter are moved out through the orifice l5 by the reciprocating grate 2|.

The plate 60 is supported in its position above the rear end of the guide or supporting plate 20 and is reciproc'ated by means of pins 63 carried by the. outer ends of arms 64 and engaging between spaced projections 65 fixed to the rear face of the plate 80. The arms 64 are fixed to an operating shaft 66 which extends outside of the furnace, as shown in Fig. 1, and is provided at its outer end with an arm 61 fixed thereto and havinga retractable latch 68 at its outer end which engages any desired one of aseries of notches 69 formed on the outer arcuate surface of an arm 10. The arm IO-is loosely mounted on the extreme'outer end of the shaft 66 and is provided with a depending arm portion 1| which is connected at its outer end to one end of an operating link 12, the other end of the link 12 being pivotally connected to the arm 41 by a pin 13 filling a preselected one ,of the openings 53.

Thus, with the latch 68 -engaging a preselected one of the notches 69, oscillatory motion of the arm 41 will be transmitted through the link 12, arm 10, arm 61, shaft 65, and arms 64, to the plate 60. The amplitude of reciprocation of the plate, i. e., the total distance traveled by the plate, depends upon the particular opening 53 within which the pin 13 is fitted. By changing the pin to another of the openings 53,the amplitude of 'reciprocations of the plate 60, i. e., the total distance traveled during each reciprocation, may be varied to suit different operating conditions. The extent or size of the ash'discharge and by varying the amplitude of reciprocations of the grate H, the rate of ash discharge and the size of the ash particles may be easily varied at will forthe purposes previously explained.

What I claim and desire to secure by Letters Patent of the United States is:

1. In combustion apparatus, the combination of means defining a vcombustion chamber including upwardly extending front and rear wall portions; means providing a fuel supporting surface extending across the lower portion of the combustion chamber; the portion of .said surface adjacent the' rear wall portion terminating in the plane of said rear wall portion and being vertically spaced from the .lower end thereof to provide an ash discharge orifice extending vertically through said rear wall portion; means for feed-- ing solid fuel onto the fuel supporting surface and for discharging ash rearwardly and through the vertical orifice; an ash crushing member vertically reciprocable across the vertical orifice for crushing ash and shearing clinker formations in the ash as the-ash moves through the vertical orifice, and means for reciprocating said ash crushing member, said ash crushing member and the reciprocating means therefor being positioned rearwardly of the rear wall portion of said combustion chamber.

2. Apparatus according to claim 1, wherein the I vertically reciprocable crushing member-is provided with tooth portions which extend inwardly and overlie the adjacent end of the fuel supporting surface for engaging the ash and clinker positioned between said crushing member and the adjacent edge of the fuel supporting surface to aid in the crushing and shearing action. 7

3. In combustion apparatus,- the combination of wall structure defining a combustion chamber;

means providing a fuel supporting surface extending across the lower end of the combustion chamber; one portion of the wall structure terminating above thefuel supporting surface todefine therewith a vertically-extending ash discharge orifice at one side of the chamber to permit the discharge of ash from said chamber; the I fuel supporting surface includinga movable portion for feeding the ash across the combustion chamber and through said verticalorifice and-a stationary portion terminating in the plane of said one portion 'ofthe wall structure; a vertically reciprocable ash crushing member partially closing said vertical orifice and vertically reciprocable across said orifice toward and from the stationary portion of the fuel supporting surface and transversely of'the direction of movement of ash through the orifice for crushing the ash, and means for constantly reciprocating said ash crushing member.

4. Apparatus according to claim 3, 'wherein means is provided for changing the position of the constantly reciprocating ash crushing member with respect to the stationary portion of the fuel supporting surface so as to vary the vertical 1 extent of saiikorifice to thereby vary the rate of the ash dischargg therethrough. I

5. Apparatus according to claim 3, wherein orifice may be varied.

means is provided for varying the amplitude of the vertical reciprocations of the constantly reciprocating ash crushing member so as to vary ber terminates above the outer edge of- .the stationary portion of the fuel supporting surface and teeth are provided on the combustion chamberv side of the ash crushing member for feeding ash'downward so that the ash canvbe ejected through the orifice.

,"7. In combustionapparatus, the combination of upright wall means defining acombustion chamber; fuel supportingmeans extending across the lower part of saidcombustion chamber and comprising a movable front portion and a stationary rear portion; thewall means at the rear the rear edge of the stationary rear portion of the fuel supportingmeans to define therewith a vertically-extending ash discharge orifice; means for-feeding fuel onto the movable front portion of said 'fuel supporting means; means for feeding ash rearwardly across the stationary portion of said supporting means and through said ver- 'tical' orifice; an ash crushing member extending across the upper part of the rear edge of the stationary rear portion of the orifice and movable vertically toward and away from said fuel supporting surface to engage and crush the ash as it moves through said orifice; and means for vertically reciprocating said ash crushing member, said ash crushing member and the reciprocating means therefor being positioned outside of said combustion chamber.

8. In combustion apparatus, the combination of upright wail means defining a combustion chamber; fuel supporting means extending across the'lower part of said combustion chamber and comprising a movable front portion and a stationary rear portion; the wall means at the rear of said chamber terminating immediatelyabove the rear edge of the stationary rear portion of the fuel supporting means to define therewitha vertically-extending ash discharge orifice; means for feeding fuel onto the movable. front portion of said fuel supporting means; means for feeding ash rearwardly across the stationary portion of said supporting means and through said vertical orifice; a, vertically reciprocable ash crushing member extending across the upper part of said of. said chamber terminating immediately above orifice and including'a lower ash crushing part;

and means providing for vertical bodily reciprocal movement of the ash crushing membertoward and away from the rear edge of the staportion the lower part of said member engages and crushes the ash as the ashmoves through the vertical orifice; said last-mentioned means including an element which may be adjusted to vary the vertical extent of the discharge orifice so that the amount of ash fiowing through the l 9. In combustion apparatus, the combination -.of upright wall means defining a combustion chamber; fuel supporting means extending across the'lower part of said combustion chamber and comprising a movable front portion and a stationary rear portion; the wall means at the rear of said chamber terminating immediately above the rear edge of the stationary rear portion of the fuel supporting means to define therewith a vertically-extending ash discharge orifice; means for feeding fuel'onto the movable front portion of said fuel supporting means; means for feeding ash rearwardly across the stationary rear portion of said supporting means and through said vertical orifice; a vertically reciprocable ash crushing member extending across the upper part of said orifice and including a lower ash crushing part; and means providing for vertical bodily reciprocal movement of the ash crushing member toward and away from the rear edge of the stationary rear portion of the fuel supporting surface and across said vertical orifice so that as the member moves toward said stationary rear portion the lower part of said member engages and crushes the ash as the ash moves through the vertical orifice; said last-mentioned means including means for varying the amplitude of the vertical reciprocal movement.

10. In combustion apparatus, the combination of upright wall means defining a combustion chamber; fuel supporting means extending across the lower part of said combustion chamber and comprising a movable front portion and a stationary rear portion; the wall means at the rear of said chamber terminating immediately above the rear edge of the stationary rear portion of the fuel supporting means to define therewith a vertically-extending ash discharge orifice; means for feeding fuel onto the movable front portion of said fuel supporting means; means for feeding ash rearwardly across the stationary rear portion of said supporting means and through said vertical orifice; a vertically-reciprocable ash crushing member extending across the upper part of said orifice and including a lower ash crushing part; and means providing for vertical bodily reciprocal movement of the ash crushing member toward and away from the "rear edge of the'stationary rear portion of the fuel supporting surface and across said vertical orifice so that as the member moves toward said stationary rear portion the lower part of said member engages and crushes the ash as the ash moves through the vertical orifice; said last-mentioned means including an element which may be adjusted to vary the vertical extent of the discharge orifice so that the amount of ash flowing through the orifice may be varied, and means for varying the amplitude of the vertical reciprocal movement of said member.

11. In combustion apparatus, the combination of upright walls defining a combustion chamber; means providing a fuel supporting surface extending across the lower part ofsaid combustion chamber; one of said walls terminating above the adjacent part of said surface to provide an ash discharge orifice at one side of said chamber; means for feeding fuel onto said surface and for moving ash through said orifice; upright guide means adjacent said one wall and at the walls defining each end of said orifice an ash crushing plate extending lengthwise across said orifice from end to end thereof and having its end parts supported for upward and downward movement .in saidguide means and having a lower surface for engaging and crushing the ash; a shaft adjacent said plate and extending in the direction of length of the plate and being supported for oscillatory movement; power transmitting means connecting said plate and said shaft for supporting said plate with its'lower surface above the level of the fuel supporting surface when the shaft is stationary and for reciprocating said plate upward and downward when said shaft is oscillated; and meansfor imparting oscillatory movement to said shaft.

12. In combustion apparatus, the combination of upright walls defining a combustion chamber; means-providing a fuel supporting surface extending across the lower part of said combustion chamber; one of said walls terminating above the adjacent part of said surface to provide an ash diseharge orifice at one side of said chamber; means for feeding fuel onto said surface and for moving ash through said orifice; upright guiLe means adjacent said one wall and at the wals defining each end of said orifice; an ash crushing plate extending lengthwise across said orifice from end to end thereof and having its end parts supported for upward and downward movement inlsaid guide means and having a lower surface for engaging and crushing the ash; a shaft adjacent said'plate and extending in the direction of length of the plate and being supported for oscillatory movement; power transmitting means connecting said plate and said shaft for supporting said plate with its lower sur face above the level of the fuel supporting surface when the shaft is stationary and for reciprocating said plate upward and downward when said shaft is oscillated; and means for oscillating said shaft including a first operating arm loosely. journalled on said shaft and having a toothed sector part, a second arm fixed at one end to said shaft adjacent said first arm and having a retractable latch device at its outer end engaging one of the teeth of saidsector, and means for oscillating said first arm.

13. In combustion apparatus, the combination of upright walls defining a combustion chamber; means providing a fuel supporting surface extending across the lower part of said combustion chamber; one of said walls terminating above the adjacent part of said surface to provide an ash discharge orifice at one side of said chamber; means for feeding fuel onto said surface and for moving ash through said orifice; up-

the walls defining each end of said orifice; an ash crushing plate extending lengthwise across said orifice from end to end thereof and having its end parts supported for "upward and downward movement in said guide means and having a lower surface for engaging and crushing the ash; a shaft adjacent said plate and extending in the direction of length of the plate and being supported for oscillatory movement; power transmitting means connecting said plate and said shaft for supporting said plate with its lower surface above the level of the fuel supporting surface when the shaft is stationary and for reciprocating' said plate upward and, downward when said shaft is oscillated; and means for oscillating said shaft including a first operating arm loosely journalled on said shaft and having a toothed sector part, a second arm fixed at one end to said shaft adjacent said first arm and having a retractable latch device at its outer end engaging one of the teeth of said sector, and means for oscillating said first arm and including means for varying the amplitude of such oscillations.

' DONALD J. MOSSHART.

right guide means adjacent said one wall and at 

